This paper addresses the question to what extent the performance of industrial sites is affected by their local economic structure and accessibility. For this aim, we test for the existence of statistically significant relationships between agglomeration externalities (specialization, diversity, and competition), accessibilty measures and the employment growth of a particular industry on a particular site. We use data on employment growth of site-industries on 68 formal industrial sites in the municipality of Amsterdam between 1998 and 2006. We show that at the site-industry level, specialization hampers growth. Furthermore, we find that industrial sites that are easily accessible from the highway grow relatively fast, as well as sites located in the Amsterdam harbour area.